Exercising apparatus, weight lifting machines or rehabiliation machines are frequently used to improve the overall health, fitness and constitution of the human body. One disadvantage of these machines is their limitation to exercise a muscle without considering its specific physical conditions during various stages of motion. Thus, the muscle is inevenly trained rendering the use of such machines on a competitive level or during rehabilitation less favorable. Moreover, these machines are usually designed for exercising either the arm or the leg so that a variety of exercising machines is necessary to work out all different kinds of muscles or at least complicated modifications of these machines are required to achieve a desired versatility.